The 925 HD combines the new computer-controlled parallactic AVX mount with the Edge HD system. With an aperture of over 23 cm and the StarBright XLT coating, it collects more than 1000 times more light than the naked eye. Thanks to the good image sharpness, it is an excellent device for astrophotography.
EdgeHD Optics
New optical design
The EdgeHD optics (Edge High Definition) combine the compact design of a Schmidt-Cassegrain with significantly improved imaging at the edge of the image. This optical system not only offers the properties of astrographs, but also produces completely undistorted, sharp images right up to the edge of the large visual and photographic field of view. Not only is the coma outside the optical axis corrected - as with other so-called "coma-free" optical designs available on the market (see also our test image) - but also the image field curvature!
The difference
Many optical systems are propagated as "astrographs"; however, they produce the coveted "pinpoint" star image along a curved image plane. On images taken with modern CCD cameras, the result is a noticeable curvature of the image field which increases towards the edge of the image field and becomes stronger the larger the chip is; i.e. the stars remain round, but are blown up into small rings ("donuts") towards the edge.
With the CELESTRON Edge HD telescopes, in addition to the coma, this image field curvature is also corrected out to the edge so that even images with large CCD chips are completely sharp, with uniformly large star images over the entire chip - right into the corners of the image field.
This also significantly improves resolution and limiting magnitude compared to competing optical systems of similar aperture. The Celestron XLT multi-coating also helps the Edge HD optics to achieve a significant increase in performance compared to similar systems on the market. Even at the edge of the field of view of a DX chip, the stars are less than 1.5 arc seconds in size.
The EdgeHD optics image three times flatter in the field plane than a standard Schmidt-Cassegrain. The stars are imaged diffraction-limited on the entire chip of a Nikon D3 or Canon 5D!
In addition to the optics, the mechanics and tube have also been completely redesigned. The innovations include:
Mirror locks hold the primary mirror in any focus position without exerting pressure on the optical elements. The image always remains stable on the chip, even with long exposure times.
Ventilation openings behind the primary mirror ensure rapid air exchange so that the optics cool down unrivaled quickly. Thanks to an air filter system, no dust gets into the tube.
HyperStar compatible - With all EdgeHD tubes, you can remove the secondary mirror and replace it with the optional HyperStar optics. The result: Your standard Celestron EdgeHD telescope becomes a digital Schmidt design for your CCD or DSLR camera for primary focus photography at f/2 (C8, C11) and f/1.9 (C14).
Learn more about this system on the dedicated EdgeHD website.
Customized telecompressors (f/7.5) and Barlow lenses (f/20) are under development.
The Advanced VX mount
The Advanced VX telescopes set the standard for medium-sized telescopes. The requirements for astrophotography in particular were taken into account when developing the mount. The Advanced VX offers many of the features of the large Celestron equatorial mounts at a very attractive price.
The Advanced VX is designed as an ideal platform for astrophotography with smaller telescopes. For telescopes up to approx. 15 kg (depending on the lever), the sophisticated functions of our large equatorial mounts are now also available to you. Thanks to PEC (Periodic Error Correction), the periodic worm error that occurs with all mounts with classic worm gears can be compensated, so that long-exposure images are also possible. In addition, you can track objects far beyond the meridian without having to turn around immediately. This allows you to observe the most interesting part of the sky without interruption. The Advanced VX also has a much wider base than its predecessor, which further increases stability even with heavy loads. The improved motors have greater torque and are better able to compensate for a slight imbalance.
Since spring 2019, it has been supplied with the dual dovetail clamp so that telescopes with both the small CG5 rail (EQ standard) and the large CGE rail (3" standard) fit on the AVX - without additional adapters! All you have to do is move the clamping screws. Larger telescopes in particular benefit from the wider rail, which offers more stability.
Dovetailplates from third-party suppliers
Vixen
The Advanced VX is still compatible with dovetail bars in Vixen format. However, the rail must be at least 100 mm long, as the clamping points of the new AVX are 90 mm apart. If a user wants to use the AVX with a telescope whose Vixen (or CG-5) dovetail bar is shorter than 100 mm, the bar must be replaced with a longer dovetail bar. Appropriate rails are available from us.
Losmandy
The new AVX mount is not compatible with Losmandy D format dovetail bars. The CGE and Losmandy D formats are similar, but not identical. Losmandy rails are about one millimeter wider, while CGE plates are deeper and have more surface contact with the dovetail clamp. To use an AVX with a telescope with a Losmandy D dovetail bar, the existing bar must be replaced with a compatible dovetail bar. Appropriate rails are available from us.
State-of-the-art technology for mobile use
Celestron Advanced VX mounts set the standard for medium-sized telescopes up to approx. 15 kg. The mount was developed with the requirements of astrophotography in mind. It offers many of the features of the large Celestron mounts at a very attractive price - and the axis cross weighs only 7.7 kg!
Solid castings and heavy-duty mechanics
Based on the proven Advanced GT mount, the Advanced VX not only offers large, easy-to-grip adjustment screws and stronger motors that cope even better with unevenly distributed loads, but also a wider base for the tripod connection and an improved dual dovetail mount with two clamping screws. No premature tilting! Tracking is possible up to 20° beyond the meridian passage.
State-of-the-art software
The AVX mount is supplied with the cold-resistant, significantly more powerful NexStar+ hand controller. This provides you with modern computer control - with over 40,000 objects and German menu navigation. Thanks to the built-in clock, commissioning is even faster than before. The software automatically moves to the reference stars, you only have to center them in the eyepiece. Even the sun can be used as a reference object.
Advanced VX mounts can be controlled via Celestron PWI Telescope Control software using the PC connection on the hand controller
Polaralignment made easy
With the AVX, you no longer have to laboriously set the pole star using the polar finder: Point the mount roughly north, perform a 2-star alignment - and then call up the All-Star Polar Alignment. The software will now help you to align the mount precisely, even if you cannot see Polaris. You can look comfortably through the telescope and do not have to kneel under the polar finder (still available as an option).
Versatile and expandable
In addition to a USB port on the hand controller, the AVX also has an autoguider input and two AUX ports. Here you can connect additional, separately available expansion modules - for example, the SkyQ Link module for control via WLAN with iPhone/iPad/Windows PC or the StarSense module, with which the mount automatically approaches and perfectly centers its reference stars.
Experienced photographers will appreciate how easily this mount can be transported to a dark observation site. If you are new to astronomy or astrophotography, the Advanced VX will help you get started and can serve you well for many years to come.
